Relay



March 10, 1942. I os 2,275,531

RELAY Filed Nov. 2'7, 1940 F/G. Z

7 (PERMANENT u out 7:)

F/G. FIG. 3

INVENTOR E. L A KA 70$ ATTORNEY Patented Mar. 10, 1942 ."UNITED STATESPATENT OFFlCE RELAY Emory Lakatos, New York, N. Y., assignor to BellTelephone laboratories, Incorporated, New York, N. Y., a corporation ofNewYork Application November 27, 1940, Serial No. 387,341

3 Claim.

This invention relates to relays and more par.- ticularly to relays ofthe general type disclosed in Patent No. 2.212,830 granted August 27,1940, to C. N. Hickman and E. Lakatos in which each work circuitcontrolled by the relay is established by the conductive engagement ofan armature with a relay core member.

With the structure disclosed in the patent above referred to, it ispossible to secure only contacts which are normally open and whichbecome closed upon the attraction of the armatures into engagement withtheir associated core members or laminations. Such relays of coursewould find extensive use in telephone or other circuits but even greaterfields of use exist for relays which are provided with both normallyopen and normally closed contacts or for relays which have contactmembers operable into engagement with either front or back contacts.While it is possible to tension an armature supporting spring or a reedtype armature to such an extent as to normally hold it against a backcontact member with suflicient force to secure a suitable back contactpressure, an increase in the ampere-turns of the relay coil would berequired to overcome this tension which increase might be prohibitive ifa relay were provided with a large number of armature springs or reedtype armature operable in response to a single operating coil.

It is therefore the object of the present invention to provide means ina relay of the magnetic contact type for securing back contact closuresin a simple and economical manner and for insuring that the relay shallbe maintained in an efficient operating condition.

To attain this object the relay in accordance with the present inventionis provided, for each transfer contact unit thereof. with a field memberof magnetic iron supported at one end on a mounting bracket and havingits forward end formed as a pole-piece to which contact bars aresecured, a permanent bar magnet supported at one polar end on themounting bracket and with its other or forward polar end positionedabove the pole-piece of the field member and provided with contact bars,and a reed armature insulatedly positioned between the pole-piece of thefield member and the free polar end of the magnet and provided withcontact bars on its opposite faces for cooperation with the contact barsof the field member and of the magnet. A common operating coil surroundsthe magnets and reed armatures of all of the units Normally thearmatures are attracted toward the magnets by the permanentmagnetization thereof to engage contact bars carried by the armatureswith the contact bars carried by the magnets thereby effecting backcontact closures between the armatures and the magnets. When the coil isenergized, however, a flux is set up in each armature which flows insuch a direction that the ends of the armatures are repelled from theouter polar ends of the magnets and are attracted toward the polepiecesof the field members whereby contact bars carried by the armaturesengage the contact bars carried by the pole-pieces of the field membersthereby effecting front contact closures between the armatures and thefield members. At the same time the flux set up by the coil whichsurrounds the permanent magnets fiows in such a direction as to maintainsuch magnets fully magnetized in their original sense. The repeatedoperation of the relay, therefore, has no tendency to render thepermanent magnets thereof less effective in maintaining the requiredback contact pressures.

For a better understanding of the invention reference may be had to thefollowing detailed description thereof taken in connection with theaccompanying drawing in which:

Fig. 1 is a side elevational view of a relay constructed in accordancewith the present invention;

Fig. 2 is a top plan view of the relay disclosed in Fig. 1; and

Fig. 3 is a front end view of the relay disclosed in Fig. 1. v

The invention has been illustrated in connection with a relay having twotransfer contact units, each comprising a movable contact having a backand a front contact with which it cooperates, but it will be obviousthat a relay might have but one of such transfer units or any requirednumber of such units.

Each transfer unit comprises a field lamination I of magnetic material,a permanent magnet lamination I, an armature lamination 9 interposedbetween the field and magnet laminations and strips I0 and H ofinsulating material, such as hard rubber or fiber, interposed betweenthe armature lamination and the field lamination and between thearmature lamination and the magnet lamination. The two units areassembled side by side as disclosed most clearly in Fig. 2 and insulatedfrom each other by the spacing strip l3 of insulating material.Positioned in the assembly outside of each of the field laminations Iand insulated therefrom by an interposed strip ll of insulatingmaterial, is a coil terminal lug l5 and positioned outside of eachterminal lug is a further strip [6 of insulating material. This entireassembly is clamped between the brackets 4 and 5 by screws H whichextend through aligned holes in the bracket 4, coil terminal lugs l5,field laminations I, armature laminations 9, magnet laminations l andinsulating strips III, II, I 3, l4 and i6 and are threaded into tappedholes in bracket 5. Such screws may be insulated where they extendthrough the holes in the laminations I, I and 8 and through the holes inthe terminal lugs IS in any suitable manner as by sleeves of insulatingmaterial surrounding their shanks.

Each field lamination I is stamped from a sheet of suitable magneticmaterial into substantially an inverted U shape having a rear arm whichserves as a means of attachment between the supporting brackets 4 and 5and having a soldering terminal 2! extending rearwardly therefrom, ahorizontal portion 2 and a front or vertical arm 3 which serves as apole-piece and which is provided with a pair of contact bars 8 weldedthereto.

Each magnet lamination I is substantially L- shaped having a rear orvertical arm which serves as a means of attachment between thesupporting brackets 4 and 5 and having a soldering terminal 22 extendingrearwardly therefrom, and a horizontal arm the forward end of whichserves as a pole-piece and is provided with aspair of contact bars 8welded thereto.

Each armature lamination 9 is also substantially L-shaped and has a rearor vertical arm which serves as a means of attachment between thesupporting brackets 4 and 5 and has a soldering terminal 23 extendingrearwardly therefrom, and a horizontal arm which is in the form of aspring reed. This reed is bifurcated at its free end and has contactbars I2 welded to the two sections thus formed which are positioned tocooperate with the contact bars 8 carried by the pole-piece 3 of theassociated field lamination I and with the contact bars 8 carried by themagnet lamination I.

As previously stated, each unit also includes two spacing strips I0 andI I of insulating material. These strips together with insulating stripsI3, l4 and I6 are rectangular in shape as disclosed in Fig. 1.

The brackets 4 and 5 are also l.-shaped the base portions of which serveto clamp the assembly previously described and have out-turned flanges24 and 25, respectively, by means of which the relay may be attached toa suitable relay or apparatus rack and the horizontal arms I8 and I9 ofwhich serve as supports for the relay coil 20.

The coil 20 is supported on the ends of arms I8 and I9 of the brackets 4and 5 just back of the pole-piece arms 3 of the field laminations I andthe ends of the reed armatures 9 and magnets I extend through the centerthereof. The ends of the coil winding are connected to the outer ends ofthe coil terminal lugs I5 in any suitable manner.

Normally, due to the permanent magnets l, the ends of the reed armatures9 are attracted towards the ends of such magnets so that the contactbars I2 on one face of the armatures are in engagement with the contactbars 8 carried by the ends of the magnets 1 thereby effecting normallyclosd back contacts between the armatures and the magnets. When,however, the relay coil 20 becomes energized a flow of fiux is set up inthe armatures 9 across the air-gaps between their free ends and thepole-pieces of the field laminations I and thence through thelaminations I in such a direction that the free ends of the armatures 9become magnetized to the same polarity as the free ends of the permanentmagnets whereupon the ends of the armatures are repelled from the endsof the magnets and become attracted into engagement with the polepiecesof the field laminations I thereby effecting front contact closuresbetween the contact bars I2 carried by the armatures and the contactbars 3 carried by the field laminations I. At the same time theenergization of the coil ll sets up a fiux condition in the permanentmagnets I which is in the same sense as the permanent magnet flux andtherefore the permanent magnets are maintained fully magnetizedregardless of the frequency of the operation oi the relay. This isbelieved to be a very important feature of the present invention sinceit insures that the relay will always maintain itself in its mostefiicient operating condition.

What is claimed is:

1. In a relay, a pole-piece of magnetic material, a permanent barmagnet, a reed armature positioned between said pole-piece and saidmagnet and insulated therefrom, said armature being normally attractedinto conductive engagement with said magnet and a coil surrounding saidmagent and said armature and energizable to' cause said armature to berepelled out of engagement with said magnet and attracted intoconductive engagement with said pole-piece and to maintain the fullmagnetization of said magnet.

2. In a relay, a field lamination of magnetic material having apole-piece, a permanent magnet lamination having a tongue portion, anarmature lamination of magnetic material having a reed portionpositioned between the pole-piece of said field lamination and thetongue portion of said permanent magnet lamination, strips of insulatingmaterial interposed between said laminations, the reed portion of saidarmature lamination being normally attracted into conductive engagementwith the tongue portion of said magnet, and a coil surrounding saidmagnet tongue and the reed portion of said armature and energizable tocause said reed portion to be repelled out of engagement with saidmagnet tongue and attracted into conductive engagement with saidpole-piece and to maintain the full magnetization of said magnet.

3. In a relay, an L-shaped field lamination of magnetic material havingits short arm extending downwardly to form a pole-piece, a permanentmagnet lamination having a tongue portion extending forwardly parallelto the longer arm of said field lamination with its polar end positionedopposite to the pole-piece end of the short arm of said fieldlamination, an armature lamination of magnetic material having a reedportion positioned with its free end between the polar end of saidmagnet tongue and the polepiece end of said field lamination, the end ofsaid armature reed being normally attracted into conductive engagementwith the polar end of said magnet, strips of insulating materialinterposed between said laminations and a coil surrounding said magnettongue and said reed portion and energizable to cause said reed portiontobe repelled out of engagement with said magnet tongue and attractedinto conductive engagement with the pole-piece end of said fieldlamination and to maintain the full magnetization of said magnet.

EMORY LAKATOS.

